Core barrel well drilling apparatus



Feb. 7, 1933. R. P. SIMMONS CORE BARREL WELL DRILLING APPARATUS Filed Oct. 22, 1929 6 Sheets-Sheet 2 1NVE N T0R Fri/lard f Jim/1101s ATTORNEY Feb. 7, 1933.

R; P. SIMMONS- 1,896,106

CORE BARREL WELL DRILLING APPARATUS Filed Oct. 22, 1929 6 Sheets-Sheet 4 71 lNV ENTOR Elf/M111 St/777770126 R. P. SIMMONS CORE BARREL WELL DRILLING APPARATUS Flled Oct 22, 1929 M (D i0 '1 5 9 k i L ll 11 E Feb. 7, 1933.

Patented Feb. 7, 1933 PATENT OFFICE RICHARD P. SIMMONS, OF NEW YORK, N. Y.

CORE BARREL WELL DRILLING APPARATUS Application filed October 22, 1929. Serial No. 401,447.

The object of the invention is to provide a core barrel well drilling apparatus in which the core barrel is provided with cutting means and of a size to receive substantially all of the material removed by the cutting means; to provide a construction which rovides for the operation of the core barrel y impact to impart axial movement thereto; and generally to provide an apparatus of the kind indicated which is of comparatively simple form and susceptible of cheap manufacture.

With this object in view, the invention consists in a construction and combination of parts of which a preferred embodiment is illustrated in the accompanying drawings,

wherein:

Fig. 1 is a vertical sectional view through a well casing and the improved core barrel, showing the latter interlocked to the casing against the relative rotative movement, showing the earth retaining means retracted.

Fig. 2 is a similar view, showing the earth retaining means extended.

Fig. is a side elevation of the improved Fig. 3 is a side elevation of the shiftable retaining device.

Fig. 4 is a side elevation of the earthholdin tube which cooperates with the earth retaming device.

core barrel.

Fig. 6 is an end elevation, taken on line 66 of Fig. 3, looking in the direction of the arrows.

Fig. 7 is a cross sectional view taken on line 7-7 of Fig. 1, looking in the direction of the arrows.

Fig. 8 is a sectional perspective view of the lower well casing section or head.

Fig. 9 is a transverse sectional view taken on line 9-9 of Fig. 1, looking in thedirection of the arrows.

Fig. 10 is a transverse sectional view taken on line 10-10 of Fig. 2, looking in the direction of the arrows. I

Fig. 11 is a vertical sectional view through a core barrel construction particularly to trap rock.

Fig. 12 is a similar view showing the rock retaining means in a different position.

Fi 13 is aside elevation of the modified core Farrel.

Fi 14 is asimilar view showing an externa sleeve in a longitudinally shifted position.

' Fig. 15 is a transverse sectional view taken on line 15-15 of Fig. 12.

. Fig. 16 is a transverse sectional view taken on line 16-16 of Fig. 12, looking in thedirection of the arrows.

Fig. 17 is a transverse sectional view taken on line 17--17 of Fig. 12, looking in the direction of the arrows.

Fig. 18 is a view, partly in longitudinal and part1) in elevation, of combined well drilling units.

Fig. 19 is a similar view of another group of combined well drilling units.

Fig. 20 is another viewof still another group of combined well drilling units.

Fig. 21 is a similar view of still another group of combined well drilling units.

Fig. 22 is a similar view of still another group of combined well drilling units.

Fig. 23 is a similar view of still another group of combined well drilling units.

Referring to the accompanying drawings illustrating the invention in detail 5 designates a well casing, the lower section 5 of which will be termed the head section, and which is constructed with a tubular wall 6 having a series of longitudinally extending integral ke s 7 and a series of longitudinally extending (eyways 8, radially spaced therefrom, and coextensive with the keys 7. The keys 7 are formed with transverse keyways 7 a, which extend in the same circumferential zones, thus providing interrupted keyways to receive locking elements capable of being interlocked therewith by a relative 'rotative movement. The elements foraccomplishing this locking action are not shown in this application, but involve special keys which are movable in keys formed in a follower head which is constructed to be longitudinally interlocked with the well casin The upper end portions of the keys 7 are formed with tapered end portions 7 and the lower end portions thereof, are also formed with tapered end portions 7 threaded joint 12. This coupling head or member is provided on its lower end with threads 13, wlnch are shown to be of an 111- .ternal type, to which the drilling head 14,

.carrying expansible drill bits 15, may be coupled and uncoupled. The threads 13 'may, obviouslybe of an external type, in which case the corresponding threads of the coupling head would be internal.

The tubular wall 10 is formed with, a series of integral keys 16, which are radially spaced from each other to form longitudinal key- Ways 17 between said keys, these keys and keyways being spaced radially from each other to interlock in all positions with the radial keysand keyways of the well casing head section. Both the lower end portions 16a of said keys 16 and the upper end 'portions 16? thereof, are tapered, so that they will readily pass the internal keys 7 of the well casing head section.

There are phases of well drilling when it is desirable that the core barrel 9 be inter locked directly to-thewell casing head section, and there are other phases of well drilling when it is desirable to lower the core barrel below the well casing, and in order that the core barrel may be adapted for each of these phases,-a sleeve 18 is mounted over the tubular wall 10, by means of the screws 18a. This sleeve is formed with a series of triangular projections 18b, which are radially spaced from each otherto provide recesses to receive the tapered ends 16?) of the keys 16 of the barrel 9. j

The upper end of the tubular wall 10 is threaded to the head 19. The screws 18a are threaded into this head or end wall 19 above the threaded connection of the same with the tubular wall 10.. This head is provided with an annular recess 19a having internal screw threads 1925 on one wall thereof, in which the external'screw threaded upper ends 20a of the longitudinal bars 20 of the core barrel tube 21 are connected. The arms or bars 20 are formed integrally with the core barrel tube, and are spaced radially from each other equal distances, and this provides radial and longitudinal slots 21a therebetween. The

bars 20 are nearly one half the total length of the tube, the lower half portion of which is shown to-be imperforate, except near the lower end thereof, which is shown to be provided with a series of radial slots or openings 22 in the annular wall of said tube. These openings or slots are located in the same longitudinal zone.

barrel tube 21 the earth retaining device 23 operates. This device consists of the end wall 24a and the radially spaced flexible earth retaining bars or strips 24?), 24c and 24d. These flexible strips are spaced apart so that they will radially interlock with the bars 20 and slide between the core barrel tube 21 and the annular wall 10. The lower end portions of these flexible strips or bars are adapted to enter the slots or openings 22 of the tube 21, from the outside of said tube, so that they may be forced into radial overlapping positions inwardly of said slots 22, thus providing a transverse earth supporting and retaining mattress below the core croweded into the tube 21. The flexible strips 24?) are shown to be somewhat longer than the flexible strips 240, and the strips 24d are shorter than the strips 240 so that they will not obstruct each other when shifted to earth retaining positions across the tube 21, as shown in Figs. 2 and 10. The inner ends of the strips or bars 246 and 240 are formed tapered to assist penetration of the earth.

To the central portion of the end wall 24a of the earth retaining device 23, a ram or piston rod 25 is connected. This ram is equipped with a piston head 26 on its upper end, which works in the pressure cylinder 27, which is mounted against the head or end wall 19. This pressure cylinder is supplied with air or pressure fluid by means of the conduit or air line 28, which extends to the surface of the well.

By forcing the piston head 26 downwardly the holding strips or bars 24?) and 240 will be forced from the uppermost positions shown in Fig. 1 to the lowermost positions, shown in Figs. 2 and 10. Byforcing the piston upwardly the fingers may be withdrawn, but this operation is conducted only after the loaded core barrel tube 21 has been withdrawn fromthe well casing, by a hoisting operation to the surface of the well, and there emptied.

To the head or end wall 19 a tubular wall 29 is coupled, as by the screw joint 29a, and to the upper end of this tubular wall 29 the head 30 s coupled, as by the screw joint 30a. To the underside of this head 30 a carrier plate or metal disc 31 is mounted, as by the olts 32, and through this plate or disc the supporting rods 33 are slidable. The lower ends of the rods or bolts 33 are fixed to the head of the hammer 34, which includes the pressure cylinder 35, in whichthe reciprocating hammer or piston 36 works, and the valve 37 for controlling the direction of the stroke thereof.

This piston hammer 36 is adapted to strike against the head 19, which thus forms the anvil head of the core barrel. Coil springs 38 are mounted on the supporting bolts or rods 32, so as to cushion the rebound of the 29, and is provided with an externally threaded nipple a to which any other unit of the well drilling engineering equipment may be coupled or uncoupled.

3y removing the sleeve 18 the core barrel unit may be coupled to an underreamer unit and the two lowered through the well casing, and the core barrel unit supported by the underreamer unit below the level of the lower section or head section of the well casing.

In Figs. 11 to 17, inclusive I show a moditied form of the core barrel, wherein the use of the flexible earth retaining strips or bars is eliminated and means used which develops a crowding action on the rock particles, which are wedgedinto the core barrel tube.

This construction includes the well casing head section 5', and a tubular wall which is provided with longitudinal external keys 51 to interlock with the internal keys 7 of the well casing head section 5. This tubular wall 50 is provided with an upper portion 50a which is somewhat thicker than the lower portion 501). To the upper portion 50a the anvil head 190 is coupled by the screw joint 50'.

The lower part of the anvil head 196 is reduced and is provided with an annular recess 52, which ends at the shoulder 52a thereof, and which is widened at 52?). In this anvil head 196 the tubular wall 53 is coupled by the screw joint 5311. To the lower end of this tubular wall 53 a coupling head 54 is connecting by the screw joint 54a and to the lower end of this coupling head 54 the tubular wall 55 is connected by the screw joint 55a.

The coupling head or union 54 is provided with large external acme screw threads 5460 which engage the acme threads 57a on the coupling ring 57 which embraces the head 54. The upper end of this coupling ring is connected by the screw joint 58a to the tubular wall 58, which is adapted to slide against the inner face of the tubular wall 50. The lower end of this coupling rin is connected by the screw joint 59a to the tu bular wall 59, which slides in the tubular wall 50; and which carries the tubular coupling head 60 on its lower end, by means of the screw joint 60a. On the coupling head 60 the drill head 61, carrying the drill bits 62, is detachably secured, as by the screw joint 62'.

In the upper end of the tubular wall 50 the tubular coupling head or union 63 is connected, as by the screw joint 63a. To the underside of this tubular coupling head the plate or disc 64 is connected by the bolts 65. This plate or disc 64 carries the pressure cylinder 66 by meansof the bolts or rods 67 which slide through said plate or disc, and coil springs 68 are mounted on said bolts or rods. The lower ends of these bolts or rods are connected directly to the upper end of the pressure cylinder 66, so that these springs will be placed under compression when the cylinder is subjected to a reaction. In this cylinder the piston hammer 69 works and operates through the lower end of the pressure cylinder against the anvil head 190.-

A valve 70 controls the flow of air or other pressure fluid to the pressure cylinder, so as to operate the same in both directions. Air is supplied to this valve by means of a conduifi 71 which extends to the surface of the we Another coupling head or union 72 is connected to the head or union 63 by means of the screw joint 7 2a, and this head or union .is provided with an externally threaded nipple 72b, to which anunderreamer or other unit of a Well drilling equipment may be connected. A second conduit 71a is connected to the lower part of the valve and extends to the surface of the well. By controlling the flow of air through the conduits 71 and 710: the

direction of the stroke of the piston hammer may be controlled at the surface of the well. Any automatic type of air or pressure hammer, or other means for producing a percussive action against the anvil head 196 may be employed.

The tubular wall 55 is equipped with a ring abutment or sto 55?) mounted upon it, which is designed to imit the upward movement of the two shiftable sections 53 and 55. The tubular wall 58 is provided with an abutment or limit stop 58?) on its upper end which is designed to engage the shoulder 52a of the annular recess 52, and which is spaced downwardly from the extreme upper end of said tubular wall 58, so that said upper end will slide into and out of the recess 52. This tubular wall 58 is also provided with a ring stop 580 which is adapted to be engaged by the acme screw coupling union 54 when the shiftable tubular wall sections 58 and 59 are at their limit of downward travel in the lower end portion 50a of the tubular wall 50.

The innermost tubular wall section 55 is formed with a slot or opening 550 in its wall. The lower end 73a of the rock retaining lever 7 3 is adapted to be forced through this opening, and for this purpose said lever is pivoted at 7 31) upon the outer surface of the tubular wall 55, so that its upper end 730 will engage the spring 74, which serve to hold the lower end 73a of said lever in its outward position, or normally clear of the bore of the tubular wall 55, which forms thecore ball tube, together with the coupling union 54 and the upper tubular barrel 53.

When the well casing is rotated in a direction opposite to the usual direction of turning used in rotary drilling, and at the same time raised, the resistance ofiered by the drill bits 62 will be suflicient to cause the core barrel tube sections 55, 54, and 53, to turn within the outer acme thread union 57, thus forcing the lower end 7 3a of said rockretaining lever 7 3 against the rock trapped in the combined core barrel tube, and thereby trapping the rock in the core barrel tube, due to the engagement of the outer portions of the lever 73 with the integral cam shoulder 590 formed on the inner wall surface of the tubular wall 59.

The pinching action of the lever against the rock core A is indicated in Fig. 15.

The tubular wall is equipped with a detachable sleeve which is secured in place by means of the screws 7 5a, and which performs the same function as the sleeve 18 of the core barrel construction shown in Figs. 1 to 10, inclusive.

The interlocking longitudinal keys and keyways formed in the well casing and the.

outer tubular wall'of each of the core barrels, permit the turning of the well casing for drilling, so that the core barrel will rotate thereto, the said interlocking preventing relative rotative movement of thecore barrel in the well casing,but permitting longitudinal movement, so that the core barrel may be reciprocated by being lifted and dropped in the well casing, or subjected to a percussive action, by the operation of the pneumatic hammer, or other equivalent means which may be employed for this purpose.

The core barrel well unit is adapted to be combined in line series with one or more well operating units, by means ofcouplings between the respective adjacent units, and by means of the interlocking keys and keyways between the lower or head section of the well casing and the uppermost unit of the series of units which are coupled in well line formation.

The particular grouping of well operating units will depend upon the particular geological and operating conditions encountered during the progress of a well drilling operation. The geological material always varies as the depth of penetration of the well increases, and this variation runs from soft materials to materials of various degrees of hardness.

The slope of the strata also varies from time to time, and the depth of the various layers of rock or other materials, changes as the depth of the well increases, and can never be accurately predetermined.

In Figs. 18 to 23, inclusive, I show an arrangement whereby various units are combined in well line formation, for simultaneously producing various steps necessary to the vertical deepening of the well.

Referring more particularly to Fig. 18, a combination consisting of a motor head unit 100, an underreamer unit 101, and the core barrel unit 102, the latter embracing the detail construction shown in Figs. 1 to 10, inclusive of the present application.

The motor head unit 100 is equipped with external longitudinal and parallel keys 100, designed to interlock with the internal keys and keyways of the lower or head section 5 of the well casing, so that the lower end of the housing 100*, which is equipped with a threaded coupling union 100, will extend below the lower end of the well casing head section 5. To this coupling union 100 the upper end of the reamer unit 101 is connected. This reamer unit is equipped with retractable and expansible reamer bits or tools 101, which are shifted from retracted, or inoperative positions, to expanded and cutting positions by means of the piston rod 101, and the toggle joint 101, between the frames which carry said reamer tools or bits and said piston rod. This piston rod is operated by means of an. air cylinder and pneumatic piston contained in the housing of said reamer unit, or by mechanical means enclosed therein. The reamer unit is rotated by means of the motor enclosed in the motor head unit 100 at a reduced speed, by means of the reduction gearing connected thereto and also enclosed by the housing of said motor head unit 100. The motor is indicated at 100, in the upper part of the housing 100 of said motor head unit.

The lower part of the housing 101 of the reamer unit 101 is equipped with a coupling union 101", to which the upper end of the housing 102 of the core barrel unit is connected. In this'housing the earth trapping chamber 102 is provided, into which earth is'forced as the combined three .unit equipment is progressively lowered into the ground, with the progressive deepening of the well. The lower end of the housing of the core barrel unit is equipped with drilling means 102, constructed to operate by the turning of the entire unit 102. The earth is trapped in this holding chamber by means of the flexible holding strips 102, which are shifted downwardly through the openings 102 in the wall of the said chamber, by means of the reciprocating rod 102 similar to the one described in detail in this case. This rod is operated by a pneumatic'cylinder and piston, or other means.

By holding the well casing at the surface against rotative movement, While permitting it to descend as the depth of the well is increased, and the electrical motor energized, the core barrel may be rotated upon its support with the motor head unit, and both the reamer and the core barrel unit held against downward displacement from the-motor head unit and the well casing, by reason of the interlocking keys and keyways of the head section 5' of the well casing and the external I keys and ke ways of corresponding formation carried by the housing 0 the motor head unit.

' As the depth of the well is increased by progressive drilling, the detached material is forced into the earth holding chamber of the core barrel, and when this is filled it is withdrawn, together with the reamer and motor head unit, through the well casing, which is retained in its position in the well, to support the earth wall thereof against caving, and to provide a normally smooth tubular wall through which the combined motor head, reamer and core barrel units may be returned to the bottom of the well.

As the core barrel progressively removes the material in the path of the well bore, it is necessary to cut a circular bore of sufiicient diameter to permit the free movement or easy lowering of the well casing, and this is accomplished through the medium of the reamer unit, which produces a finishing out upon the wall of the material encountered in the passage of the core barrel through the ground.

In order to accomplish the various objects here outlined, of progressively cutting away the earth to form the well bore, and of intermittently removing the equipment, to discharge the trapped earth, it is necessary that the reamer tools be inwardly shiftable from wall cutting positions, to permit the reamer unit and the core barrel unit to be simultaneously withdrawn, with the motor head unit,

from the well casing. It is furthermore necessary that the coupling between the uppermo'st unit, in this case, the motor head unit, and the well casing, and the construction of the housing of each of the suspended or pendant units, be of a character to permit vertical withdrawal from the head section of the well casing, and that the latter positively prevent downward displacement of the suspended units therefrom.

There are conditions in the progress of deepening a well, which may require the manual turning of the well casing from the top 01' the well, or its turning by and means preferred from the top of the well, so that the core barrel and the reamer units may be turned slowly in the ground, and the longitudinal interlocking between the well casing and the motor head unit permits this very operation, since the interlocking prevents relative rotative movement between the motor head unit and the well casing, and the latter and all well operating units carried thereby will be rotated whenever the well casing is turned with relation to the ground itself.

There are conditions which may require the locking of the reamer unit and the core barrel to the well casing, against vertical relative movement, or slidin as when a percussive 8.0171011 1s produc against the core barrel, so as to vibrate the same, or increase the. drilling efiect produced by its drillingtools. In this case a locking head unit 103 is em loyed, which is equipped with auxiliary loc ing keys 103, which are shiftable to interlock with the transverse keyways' 7a of the well casing.

To the coupling union 103 of this coupling head, or locking coupling head, the reamer unit 101 is connected, and to the reamer unit 101 the core barrel unit 102 is connected, in the manner described with reference to Fig. 18. In this combination of units, the reamer and core barrel units are turned by the turning of the well casing, and each is operated by its own equipment, through .air

conduits passing upwardly to the top of the well, through the connected units and the well casing, the successive sections of which are coupled in line formation.

Where the geological matter encountered calls for the use of a shrapnel drilling unit, the system herein disclosed permits of the inclusion of such a unit in line formation, to produce a continuous automatic percussive action upon the reamer and core barrel, 01' upon any one or more units coupled in line formation with the sharpnel drilling unit. Referring to Fig. 20 a combination of this character is shown, which includes the shrapnel unit 104, the reamer unit 101, and the core barrel unit 102.

The shrapnel unit 104 is coupled to the well casinghead section 5 against relative rotative movement, but to permit relative sliding movement, through the external keys 104 formed on the housing 104 of said unit, which engage the internal keys formed in the well casing head section 5.

When the core barrel unit is used in combination with a percussive means, as, in this case the shrapnel unit 104, it is preferred that a toothed drill head 104*, shown in Fig. 20,1be employed on the lower end of the unit 10 There are special geological conditions encountered in the drilling of some wells which suggest the use of a shrapnel drilling unit in connection with the core barrel unit, especially when considerable material of the softer grades is met with. When such material exists for a considerable depth, rapid progress can be made by eliminating the use of the reamer, and utilizing the percussive efi'ect produced by the internal equipment or reciprocating hammer of the shrapnel drilling unit, to accelerate the drilling action of the drilling head of the core barrel. In Fig. 21 I show such a general combination, in which the core barrel unit 102 is coupled directly to the shrapnel drilling unit 104. This shrapnel drilling unit is equipped with wall drill bits 104', which may be expanded or retracted. Above the interlocked lower 'half portion of the housing 104 of said unit 104 the means for producing the percussis sive action are arranged in the upper half portion 1O4= of said housing.

In Fig. 22 I show the motor head unit 100 combined directly with the core barrel unit 102. In this case a .drilling head is used which has rotary drill bits, these bein mounted on the lower end of the housing 0 the core barrel unit. This combination would be particularly effective in very soft ground, as the core barrel unit would be continuously rotated by the motor head unit and its enclosed reduction gearing.

In Fig. 23 I show the locking head unit 103 combined in line formation withthe soft core barrel unit 102. This combination would also be used in certain conditions of drilling where considerable depth of soft materials exists, and a continuous percussive action would be maintained against the core barrel,

and it would be necessary to prevent relative longitudinal movement of the core barrel on the well casing. The use of the locking head provides means whereby the core barrel can be locked to the well casing against relative rotative movement and relative longitudinal movement.

As previously described the locking head is uipped with means for lockin the head sectlon 5' thereto against longitudinal movement, which consists of movable keys working through slots in the housing thereof, and which are adapted to engage the transverse keyways 7a of the well casing head section 5'. These movable keys are operated. by means of mechanical controls and mechanism, which can be manipulated from the top of the well.

The reamer unit, the shrapnel unit, the core barrel unit, the motor head unit, are each provided with keys adapted 'to be longitudinally aligned with each other, and to successively pass through the keyways of the well casing head section 5', as previously described with reference to the shiftable sleeves on the housing of the core barrel units. When any one of the well drilling or operating units, 100, 101, 102, 103 or 104, or all of them are coupled to ether and also coupled in series to the combined looking and coupling head, the shiftable ex ternal sleeve thereof is removed, so that each or all of such units carried by the combined locking and coupling head can pass through the lower end of the well casing headesection 5', and be suspended thereby, without danger of the working units separating from their connection with the wellcasing and droppin below the well casing and getting lost 1n t e sand pockets frequently encountered in well drilling.

The reamer unit 101 is provided with an air et 101 or a plurality thereof, which are supplied with compressed air by means of the flexibleconduit 101, which extends to the head of the well. When the drilling units supported by the well casing are withdrawn in stable earth or rock material, forming the wall of the well chamber below the well casing, would have a tendency to collapse, thus filling this chamber. Since the withdrawal of the drilling units would take place from-time to time, it is important that the wallof the well chamber below the well casingl, should be supported against collapse. his object is accomplished by maintaining an internal pressure against the vertical wall of the well chamber, through compressed air supplied to said well chamber by means of the jet or jets 101. When the drilling units are withdrawn from the well this pressure is held against reduction by means of a land joint at the head of the well casing, an a vertical enclosing cylinder, of sufiiclent length to accommodate the withdrawn well drilling units, which is sealed at the top.

The hereinbefore described constructions admit of considerable modifications without departing from the invention; therefore, I do not wish to be limited to the .precise arrangements shown and described, which are as aforesaid, by way of illustration merely. In other words, the scope of protection contemplated is to be taken solely from the appended claims, interpreted as broadly as is consistent with the prior art.

I claim as new 1. A well drilling apparatus comprising a core barrel having cutting means at its lower end, the core barrel being of a size to receive substantially all of the material removed by the cutting means, an anvil above and operatively connected with the core barrel, and an impact member having a cushioned support from which it is swung, said member being disposed in operative relation to said anvil to drive the core barrel by successive impacts with said anvil to efl'ect the cutting and filling actions of the latter.

2. A well drilling apparatus comprising a core barrel having cutting means at its lower end, the core barrel being of a size to receive substantially all of the material removed by the cutting means, an anvil above and operatively connected with the core barrel, and an impact memberdis osed in operative relation to said anvil to rive the core barrel by successive impacts with said anvil to effect the cutting and filln actions of the latter, the impact element iaving a bodily c'ushioned support from which it depends and being supported above the core barrel- 3. A core barrel having cutters at its lower end and shaped to definea chamber for the reception of the materialloosed by said outters, the latter being positioned at the open end of said chamber, ananvil operatively connected with the corebarrel, and a pneumatic hammer positioned above said anvil for delivering successive impactsto the latter and thereby driving the core barrel, said hammer having a support and suspension springs by which the support is bodily. carmed.

4. A core barrel having cutters at its lower end and shaped to define a chamber for the reception of the material loosed byrsaid cutter, the latter being positioned at the open end of said chamber, an anvil operatively connected with the core barrel, and a pneumatic hammer positioned above said anvil for deliverin successive impacts to the latter and there y driving the core barrel, the pneumatic hammer having a cushioned sup- 5. A'well drilling apparatus comprising a well casing, a housing having an interloc ing connection with the Well casing at the lowerend of the latter to. prevent relative angular or turning movement between the two and likewise prevent the housin from dropping through the lower end of tfie casing, a core barrel open at its lower end and having cutters thereat, the core barrel being interior to the casing, an anvil above the core barrel and operatively connected thereto, and an impact tool positioned in the casing above the anvil for successive impacts with the latter.

, and operatively ioned pneumatic hammer.

' 6. A well drilling apparatus comprising a well casing, a housing aving an interlockmg connection with the well casing at the lower end of the latter to prevent relative angular or turning movement between the two and likewise prevent the housing from dropping through the lower end of the casing,.a core barrel open at its lower end and having'cut ters thereat, the core barrel being interior to the casing, an anvil above the core barrel connected thereto, and an impact tool positioned in the casing above the anvil for successive impacts with the latter, said impact tool comprising a bodily, cush- In testimony whereof I hereby signature.

RICHARD 1 SIMMONSk- 

